1. Field of the Invention
The present invention relates to a mechanical apparatus for washing/drying, and more particularly, to a structure for damping and absorbing vibration of a tub in a washer or dryer.
2. Discussion of the Related Art
FIG. 1 is a structural diagram of a drum type washer according to a related art and FIG. 2 is a cross-sectional diagram of a damper of a drum type washer according to a related art.
Referring to FIG. 1 and FIG. 2, a drum type washer consists of a washing tub 2 provided within an exterior 1 of the drum type washer, a dewatering tub 3 provided within the washing tub 2 to accommodate a laundry 6 therein, a damper 4 provided between the exterior 1 and the washing tub 2 to support and fix the washing tub 2 thereto and reduce an amplitude of vibration of the washing tub 2, a spring 5 elastically provided to an upper space between the exterior 1 and the washing tub 2 to fix and support the washing tub 2, and a leg 7 provided beneath the exterior 1 to support the drum type washer.
The damper 4, as shown in FIG. 2, consists of an outer pipe 8 assembled to an outer circumference of the washing tub 2 to have a pipe shape, an inner cylinder 9 assembled to an inner circumference of the exterior 1 to reciprocate within the outer pope 8 by the vibration of the washing tub 2, and a lubricative member 10 provided between an inner circumferential part of the outer pipe 8 and an outer circumferential part of the inner cylinder 9 to generate a frictional force for alleviating the amplitude of the vibration of the washing tub 2.
After the laundry 6 has been loaded in the dewatering tub 3 provided with the washing tub 2, if a power is applied to the above-configured drum type washer, water is introduced into the washing tub. Once a prescribed quantity of the water is introduced, the dewatering tub 3 is rotated to wash the laundry 6.
After completion of the washing of the laundry 6, the laundry 6 is dewatered. In a transition state that a considerable force is instantly applied to the dewatering tub 3 in initiating the dewatering, the laundry 6 inclines to generate imbalance. While the imbalance is maintained, the dewatering tub 3 is rotated at high speed to perform the dewatering of the laundry 6. So, an amplitude of vibration of the washing tub 2 increases.
Yet, in a normal status, the dewatering tub 3 is smoothly rotated to perform the dewatering of the laundry 6, whereby the vibrational amplitude of the washing tub 2 decreases.
In order to reduce the vibrational amplitude generated from the washing tub 2 due to the imbalance attributed to the incline of the laundry 6 in the transition state for the dewatering initiation of the laundry 6, the damper 4 is provided between the exterior 1 and the washing tub 2 of the drum type washer. So, the vibrational amplitude of the washing tub 2 can be reduced.
The vibrational amplitude of the washing tub 2 is reduced by a vertical force N between an inner circumference of the outer pipe 8 and an outer circumference of the inner cylinder 9 reciprocated within the outer cylinder 8 by the vibrational amplitude of the washing tube 2 or by a frictional force FN with the lubricative member 10 provided to increase the coefficient of friction.
Yet, the above-configured damper of the related art is hinged to both of the tub and the cabinet and has an excessively large incline angle. So, it is unable to effectively reduce or absorb the tub vibration in a lateral direction.
A damping force of the above-configured damper of the related art is about 70˜120N to minimize a displacement of transient vibration in initial dewatering. Yet, since the damping force is excessively large, it is unable to effectively reduce the vibration in entering normal dewatering in particular. So, most of the vibration is transferred to a floor on which the washer including the cabinet is installed.
In this case, if the damping force of the related art damper is reduced to decrease the transferred force of the vibration, the displacement in the transient vibration is increased to cause a problem.
To effectively reduce the vibration of the normal dewatering as well as the vibration of the initial dewatering and to minimize the displacement of the tub, a damping means having a new configuration is needed.
Besides, the damping means is applicable to a dryer, for which tub vibration needs to be reduced, as well as a washer.
A dryer is a well-known mechanical device for drying laundry and its details will be omitted in the following description.